A gas turbine engine typically includes a fan section, a compressor section, a combustor section, and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
During certain operating conditions for the gas turbine engine, it may be advantageous to bleed compressor air off of the compressor section through a bleed duct by opening a bleed valve. In particular, bleeding air from the compressor section can reduce instability in the compressor section that may result from surges in pressure. However, air flowing across the bleed duct when the bleed valve is closed may create a resonance in the bleed duct. The resonance could cause vibrational waves to travel through compressor blades adjacent the bleed duct resulting in unwanted stress on the compressor blades. Therefore, there is a need to prevent the formation of vibrational waves traveling through the bleed duct when the bleed valve is closed.